Dr. Pole began by stating it was not the object of the paper to meddle with the practice of harmony, as determined by the best composers; nor with the teaching of harmony, so far as it was of a practical nature. Students must be taught what they were to do, and their instruction was generally efficient and admirable. But the writers of books on harmony were often not content with practical teaching; they thought it necessary to bring forward systems and theories with the object of explaining, deriving, and accounting for all the facts of harmony on grounds of natural necessity. The first who attempted this was Rameau, in 1722, who was a philosopher as well as a musician, and whose system, though it did not go far, was novel and useful, and laid the foundation for all that had been done since. But harmony had much extended since his day, and later theorists had supplemented Rameau's principles by theories and hypotheses of much more doubtful authority; hence had arisen a host of different systems, so conflicting and inconsistent that, instead of aiding the study of harmony, they were only calculated to throw stumbling-blocks in its way. A reaction had set in, and many of the best authorities had lately been inclined to doubt the possibility of explaining all the facts and rules of harmony on natural principles; many opinions to this effect being quoted in the paper.